TinyMCE：图标不可见

如果我直接在下载的TinyMCE包中使用html文件，则会出现图像图标;如果将其用作Web应用程序，则其所有功能都可以正常工作。但是图标却没有出现。我使用的是TinyMCE 4.0.28版本。

初始化脚本：

tinymce.init({
    relative_urls : false,
    remove_script_host : false,
    convert_urls : true,
    selector: "textarea#elm1",
    theme: "modern",
    width: 800,
    height: 500,
    plugins: [
         "advlist autolink link image lists charmap print preview hr anchor pagebreak spellchecker",
         "searchreplace wordcount visualblocks visualchars code fullscreen insertdatetime media nonbreaking",
         "save table contextmenu directionality emoticons template paste textcolor"
   ],
   toolbar: "insertfile undo redo | styleselect | bold italic | alignleft aligncenter alignright alignjustify | bullist numlist outdent indent | l      ink image | print preview media fullpage | forecolor backcolor emoticons", 
   style_formats: [
        {title: 'Bold text', inline: 'b'},
        {title: 'Red text', inline: 'span', styles: {color: '#ff0000'}},
        {title: 'Red header', block: 'h1', styles: {color: '#ff0000'}},
        {title: 'Example 1', inline: 'span', classes: 'example1'},
        {title: 'Example 2', inline: 'span', classes: 'example2'},
        {title: 'Table styles'},
        {title: 'Table row 1', selector: 'tr', classes: 'tablerow1'}
    ]
 }); 

更新：包括其他图像。

技术 ：

我已经使用过Servlet API，没有其他机制。

FireBug的HTML用于斜体图标：

<button tabindex="-1" type="button" role="presentation">
 <i class="mce-ico mce-i-emoticons"></i>
</button>

web.xml：

<!-- To map all the static contents below code starts -->
<servlet-mapping>
    <servlet-name>default</servlet-name>
    <url-pattern>*.html</url-pattern>
</servlet-mapping>
<servlet-mapping>
    <servlet-name>default</servlet-name>
    <url-pattern>*.jpg</url-pattern>
</servlet-mapping>
<servlet-mapping>
    <servlet-name>default</servlet-name>
    <url-pattern>*.png</url-pattern>
</servlet-mapping>
<servlet-mapping>
    <servlet-name>default</servlet-name>
    <url-pattern>*.css</url-pattern>
</servlet-mapping>
<servlet-mapping>
    <servlet-name>default</servlet-name>
    <url-pattern>*.js</url-pattern>
</servlet-mapping>
<servlet-mapping>
    <servlet-name>default</servlet-name>
    <url-pattern>*.gif</url-pattern>
</servlet-mapping>
<!-- To map all the static contents below code ends -->

<!-- To map all the non-static contents below code starts -->
<servlet>
    <servlet-name>ControllerServlet</servlet-name>
    <servlet-class>tut.core.Controller</servlet-class>
</servlet>

<servlet-mapping>
    <servlet-name>ControllerServlet</servlet-name>
    <url-pattern>/</url-pattern>
</servlet-mapping>
<!-- To map all the non-static contents below code ends -->

问题 ：

为什么只有斜体图标无法使用，因为它无法处理情绪等？但是其他图像却可以正常显示。